This proposal is to continue the support of training in cancer research at Columbia University College of Physicians and Surgeons. Funds are requested to continue the support of 8 predoctoral trainees per year and to expand the program to include 4 postdoctoral trainees. The aim of the program is to provide to individuals state-of-the-art training in the most relevant areas of modern cancer research including molecular genetics, cell biology, virology, immunology, molecular pathology, and experimental therapeutics. The participating faculty has been selected for the direct relevance of their research to the study of various aspects of the cancer problem. Trainees are chosen competitively on the basis of excellence and relevance of their project to cancer research. Trainees are required to take formal course work and seminars to provide an extensive exposure to the current state of cancer research and its future directions.